Born in Lancaster, in England, on 6 January 1896, Gardner emigrated to Western Australia with his family in 1909, where they took possession of land at Yorkrakine.
[1][2] Gardner showed an interest in art and botany from youth, becoming engrossed in his state museum's copy of Bentham's Flora Australiensis (London, 1863–78) and received encouragement from the government's botanist Desmond Herbert and botanical artist Emily Pelloe.
[1] After a BSc in biology, he was appointed a botanical collector for the Forests Department in 1920, and the following year was engaged as botanist on the Kimberley Exploration Expedition, resulting in his first publication, Botanical Notes, Kimberley Division of Western Australia, which gave descriptions for twenty new species.
In 1924 he transferred to the Department of Agriculture, and following a departmental re-organisation in 1928 he was appointed Government Botanist and Curator of the State Herbarium.
His personal botanical collection was bequeathed to the Benedictine Community at New Norcia, but was transferred to the State Herbarium in Perth in June 1970.